Elevator filing appliance



June 1, 1965 c. D. GRABER 3,186,783

ELEVATOR FILING APPLIANCE Filed Feb. 11, 1963 5 Sheets-Sheet 1 Fig. 1

2 INVENTOR. Uwrb D. Grabber BY 9mg, W8: W

ATTORNEYS V June 1, 1965 c. D. GRABER ELEVATOR FILING APPLIANCE 5Sheets-Sheet 2 Filed Feb. 11, 1963 INVENTOR. Ca/rb D. Lira/bez-ATTORNEYS June 1, 1965 c, GRABER 3,186,783

ELEVATOR FILING APPLIANCE Filed Feb. 11, 1963 5 Sheets-Sheet 3 INV ENTOR.

CwrLD. Gnuber BY 9M0, ,lo%4& M

ATTORNEYS June 1, 1965 c. D. GRABER 3,185,783

ELEVATOR FILING APPLIANCE Filed Feb. 11, 1963 5 Sheets-Sheet 4 INVENTOR.

UwrL D. Gzwber ATTORNEYS June 1, 1965 c. D. GRABER ELEVATOR FILINGAPPLIANCE 5 Sheets-Sheet 5 Filed Feb. 11, 1963 nvmvrm Uwrb D. Grater BY7 94mg, ATTORNEYS United States Patent 3,186,783 ELEVATQR FELHJGAPPHANCE Carl D. Graher, (Prrvilie, Qhio, assignor to Diehoid,Incorporated, Canton, (thin, a corporation of (Bhio Filed Feb. 11, 1963,Ser. No. 257,4ti8 4 marinas. (Cl. 312-268) The invention relates tofiling appliances of a type generally known as an elevator file in whicha number of card-holding pans are mounted on and connected at each endto pairs of continuous drive and stabilizing chains suppported on anddriven by vertically spaced chain sprockets so that upon movement of thechains by a drive motor, any pan can be moved to a work station adjacentan opening in the appliance case or housing. More particularly theinvention relates to improved synchronizing means for the drive of thepairs of drive and stabilizing chains, and the synchro-driveconstruction of the invention is an improvement upon the constructiondescribed in my Pat. No. 2,940,810.

Problems have arisen in the construction and operation of elevator filessuch as shown in Pat. No. 2,940,810 where the height of the pans isincreased to accommodate taller cards carried by the pans. The problemis complicated by two factors; first, the increased card height or sizeincreases the load carried by any pan when fully loaded with cards, andsecond, the V-arranged lever arms on which the pans are mounted must bespaced further apart on the chains to accommodate the taller cards andthe increased pan height.

The increased spacing of the V-arranged lever arms on the chains and theheavier loading on the pans combine to impart forces causing the chainsto tend to assume a wave-like shape along their extent.

These conditionsthe heavy pan loading, the increased pan spacing, andthe resultant wave-like chain shaperequire absolute synchronism to bemaintained at all times in the movements of the drive and stabilizingchains of each pair at the ends of the pans mounted on and driven by thechains, in order for the elevator file to function properly with smoothand noiseless operation and free of any tendency to jam, lock or bindthe drive or to upset the pans.

Furthermore, an increase in the pan height in an elevator file ofmaximum capacity for a given size of file results in interferencebetween the pans and the main drive shaft extending across the top of anelevator file such as shown in Pat. No. 2,940,810 as the pans movearound the top of their orbit of movement. The main drive shaftextending across the appliance at the top must be relocated at thebottom of the file in order to eliminate such interference.

Pat. No. 2,940,810 has one type of means for synchronizing the movementsof the drive and stabilizing chains of each pair at each end'of the pansmounted on the chains. This synchronizing means utilizes a pair ofsynchronizing sprockets rotating together and engaged one with each ofthe pair of drive and stabilizing chains intended to tie and coordinatethe movements of the drive and stabilizing chains. In order to beeffective, both such synchronizing sprockets must at all times be fullyengaged with their respective chains. For this purpose an idler orback-up sprocket engages the stabilizing chain adjacent the engagementof the stabilizing chain with one of the synchronizing sprockets tomaintain the stabilizing chain in engagement with its synchronizingsprocket.

While this type of cynchronizing means is effective to synchronize themovements of the drive and stabilizing chains in elevator files havingpans not too heavily loaded of the size and number shown in the patent,it has been Patented dune l, 1955 found that such synchronizing means isnot fully effective when used on larger elevator files having pans ofincreased height, with increased pan spacing, and with more heavilyloaded pans. This lack of effectiveness results because the drive chain,due to heavy loading and wavelike chain action releases itssynchronizing engagement with its synchronizing sprocket, since it isnot positively maintained at all times in full and complete engagementwith its synchronizing sprocket by any backup sprocket. Due tointerference with the V-arranged lever arms on which the pans aremounted on the drive chains, n is not possible to provide a back-upsprocket for the drive chain synchronizing sprocket.

This limitation as to the effectiveness of the synchronizing means forthe elevator file of Pat. No. 2,940,810 has limited the capacity as topan size, card size, pan loading, etc., that can be used in properlyoperating elevator files constructed as shown in the patent.

Thus, a need has arisen for a synchronized drive for larger capacityelevator files of the type shown in Pat. No. 2,940,810, which largercapacity files cannot be eliectively synchronized by the synchronizingmeans of the patent.

I I have discovered a solution for this problem satisfying the needwhich comprehends positively and directly tying together andsynchronizing separate drives for each of the drive and stabilizingchains of each pair of chains at the ends of the pans supported on anddriven by chains.

In accordance with the invention, an inter-connecting chain positivelyties the drive for the drive chain with t e drive for the stabilizingchain of each pair of drive and stabilizing chains. This inter-chain ismaintained tight or taut by adjustable idler sprocket means. Finally,means is provided to compensate for any change in efiective length(involving idler sprocket adjustment to maintain inter-chain tautness)of the inter-chain so that matching orientation of the drive shafts ofthe drive and stabilizing chains can be maintained at all times with anyposition of idler sprocket adjustment.

Accordingly, it is a general object of the present invention to providean improved synchronizing drive for an elevator file having a series ofpans mounted on, connected to and driven at each end by pairs ofcontinuous drive and stabilizing chains.

Furthermore, it is an object of the present invention to provide animproved and ei fective synchro-drive construction for elevator fileshaving heavily loaded, tall-cardcontaining pans supported and driven bypairs of continuous drive and stabilizing chains at the ends of thepans.

lso, it is an object of the present invention to provide an improvedsynchro-drive construction for elevator files having pans supported anddriven by pairs of continuous drive and stabilizing chains at the endsof the pans, which positively functions to maintain drive synchronismwithout limitation as to pan size, card size, or pan loading.

Moreover, it is an object of the present, invention to provide a newsynchro-drive construction for elevator files having pans supported anddriven by pairs of continuous drive and stabilizing chains at the endsof the pans, in which separate drives for each of'the drive andstabilizing chains are directly tied together and absolute synchronismof the movements of the drive and stabilizing chains is maintained atall times.

In addition, it is an object of the present invention to provide a newsynchro-drive construction for elevator files having pans supported anddriven by pairs of continuous drive and stabilizing chains at the endsof the pans, in which an inter-connecting chain positively ties thedrives for the drive and stabilizing chains of each pair, in which theinter-connecting chain may be maintained taut at all times, in whichmeans is provided to compenr 9 sate for any change in the effectivelength of the interconnecting chain so as to maintain at all timesmatching the ends of the pans extending across thefile at the bot.

tom of the file to eliminate interference between such shaft andrelatively high pans adapted for containing tall cards, during movementof the pans throughout their path of travel.

Finally, it is an object of the present invention to provide a newsynchro-drive construction for elevator files eliminating thedifliculties heretofore encountered in the art; achieving the statedobjects in a simple, effective and inexpensive manner; and solving theproblems of limited pan size, card size, pan loading, etc., existing inthe art.

These and other objects and advantages, apparent to those skilled in theart from the following description and claims, may be obtained, thestated results achieved, and the described dil'iiculties overcome, bythe apparatus, combinations, parts, elements, subcombinations,arrangements and constructions which comprise the present invention, thenature of which is set forth in the following general statement, apreferredembodiment of whichillustrative of the best mode in whichapplicant has contemplated applying the principles is set forth in thefollowing description and shown in the drawings, and which areparticularly and distinctly pointed out and set forth in the appendedclaims forming part hereof.

The-nature'of the improved elevator file construction of the presentinvention may be stated in general terms as including in an elevatorfile of a type having a plurality of card-holding pans supported on anddriven by pairs of continuous drive and stabilizing chains at the endsof the pans, and a pair of vertically'spaced chain sprockets for eachdrive and stabilizing chain, all mounted on a base and frame supportstructure; the combination of means mounting one of the sprockets ofeach pair on drive-transmitting-shaft means, means mounting the othersprocket of each pair on idler shaft means, a synchronizing sprocketmounted oneach drive-transmitting-shaft means, a continuousinter-connecting chain in driving engagement withsaid-synchronizingsprockets, adjustable idler sprocket means engaged with theinter-connecting chain for maintaining the inter-connecting chaintaut,one

of the synchronizing sprockets being rotatably adjustable with respectto the shaft means on which it is mounted, a. motor-driveoperativelyconnected preferably with the drive shaft means for one of the drivechain sprockets, and preferably the drive shaft means for the lowerdrive chain sprocket at one end of the pans extending across theappliance to'formthe drive shaft means for the lower drive chainsprocket at the other end of the pans.

Byway of example, an embodiment of the improved elevator fileconstruction is shown in the accompanying drawings forming part hereofin which:

FIGURE 1 is a front elevation, with certain parts in section and othersin dot-dash lines, of the pan support and drive mechanism of theimproved elevator file omitting the outer housing of the appliance;

FIG. 2 is a section looking in the direction of rows 2-2, FIG. 1; a

FIG. 3 is a view similar to FIG. 2 looking in the direction of thearrows33,'FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view of the upper left-handcorner of the parts shown in FIG. 1;

FIG. 5 is a view similar to FIG4 of the parts shown in the lowerleft-hand corner of FIG. 1;

FIG. 6 is an end elevation of the left-hand side of the parts shown inFIG. 1;

FIGS. 7, 8 and 9 are diagrammatic views illustrating the arthe mannerin'which the improved synchronizing means may be adjusted; and

FIG. 10 is a diagrammatic view of the complete drive and pan supportmechanism of the improved file.

Similar numerals refer to similar parts throughout the drawings.

The improved synchro-drive for an elevator file of the type shown inPat. No. 2,940,810 is illustrated in the drawings, FIG. 1 illustratingthe pan support and drive mechanism. One pan is shown in full lines atthe top and another pan is shown in full lines at the bottom of theorbit of pan movement in FIG. 1 and the remaining pans have been omittedfor clarity. The pans also are omitted in FIGS. 2 and 3, excepting thatthe location of one pan is illustrated in dot-dash lines in FIG. 2.

The improved elevator file is indicated generally at 1 and includes abase structure '2 and spaced upright end frame members 3 and 4. Upperdrive support members 5 and lower drive support members 6 are mounted onthe facing surfaces of the end frame members 3 and 4 by bolts 7. Achannel stretcher member 8 is connected tothe upper support members 5 tocomplete a generally rectangular frame and support structure emendingupwardly from the base 2.

Main drive shaft 9 is journaled at its ends in bearings 10 and 11carried by the lower drive support members 6 in the bottom region of thefile 1 (FIGS. 1 and 5). A drive chain lower drive sprocket 12 is keyedto shaft 9 adjacent an inner surface of each lower support member 6.- Adrive chain upper idler sprocket 13 is journaled on stub shaft 14mounted at the upper end of each upper drive support member 5. Each stubshaft 14 also is supported by a recessed pad 15 mounted on a shieldplate 16 extending upward from channel member 8.

Idler sprocket 13 adjacent frame. member 3 is spaced above and alignedwith drive sprocket 12 adjacent frame member 3, thus providing a pair,of sprockets around which continuous left-hand drive chain 17 istrained. Similarly, idler sprocket 13 adjacent frame member 4 is spacedabove and aligned with drive sprocket 12 adjacent frame member 4 thusproviding a pair of sprockets around which continuous right-hand drivechain 18 is trained.

A stabilizing chain drive shaft 19 is journaled in bearings 20 and 21 atthe upper end of each upper support member 5 and a stabilizing chainupper drive sprocket 22 is keyed to each shaft 19 between bearings 20and 21.

A stabilizing chain lower idler sprocket 23 is journaled on stub shaft24'at the bottom end of each lower support member 6. The sprockets 22and 23 adjacent frame member 3 are aligned and spaced above one anotherand form a pair of sprockets around which continuous lefthandstabilizing chain 25 is trained. Similarly, sprockets 22 and 23 adjacentframe member 4 are aligned and spaced above one another and form a pairof sprockets around which continuous right-hand stabilizing chain 26 istrained.

The upper drive support members 5 may be adjusted toward and away fromthe lower drive support members 6 to maintain the drive and stabilizingchains 17, 18, 25 and 26 taut by adjusting screws 27; the apertures 28in the frame members 3 and 4 (FIG. 6) for the bolts 7 which mount theupper support members 5 on the frame being elongated as shown to permitsuch adjustment.

A synchronizing sprocket 29 is keyed to main drive shaft 9 adjacent eachend thereof outside the end frame members 3 and 4 (FIG. 1), and asynchronizing sprocket generally indicated at,30 is keyed to the end ofeach stabilizing chain drive shaft 19 outside the frame members 3 and 4.The pair of synchronizing sprockets 29 and 30 adjacent frame'member 3are aligned and spaced above one another and form a pair of sprocketsaround which continuous left-hand inter-connecting chain 31 is trained.Similarly, sprockets 29 and 30 adjacent frame member 4 are aligned andspaced above one another and form a pair of sprockets around whichcontinuous right-hand inter-connecting chain 32 is trained.

An adjustable idler sprocket 33 (FIGS. 1 and 6) is mounted on eachupright end frame members 3 and 4 below each synchronizing sprocket 38for engagement respectively with each interconnecting chain 31 and 32.Adjustment of sprockets 33 may be made to maintain the inter-connectingchains 31 and 32 taut. A main drive sprocket 34 is keyed to one end ofshaft 9 (FIGS. 1, 5 and 6) and is connected by chain 35 with drivesprocket 36 on shaft 37 of drive-motor 38.

The drive and stabilizing chains 17, 18, 25 and 26 are endless linkchains of the same length and pitch and each chain is trained around apair of spaced sprockets. The drive and stabilizing chain sprockets 12,13, 22 and 23 all have the same pitch line diameter and same number ofsprocket teeth and the sprockets of each pair are spaced the samedistance apart.

The synchronizing sprockets 29 and 319 also both have the same pitchline diameter and the same number of sprocket teeth so that eachsprocket of a pair tied by an inter-connecting chain 31 or 32, rotatesat the same speed as the other sprocket of the pair.

The drive of motor 38 (FIG. 10) is transmitted through shaft 37,sprocket 36, chain 35 and sprocket 34, to shaft 9; and from shaft 9through synchronizing sprockets 29, synchronizing chains 31 and 32, andsynchronizing sprockets 38 to stabilizing chain drive shafts 19. Shafts9 and 19 thus rotate the drive sprockets 12 and 22 for the drive chains17 and 18 and stabilizing chains and 26, respectively, at the samesynchronized speed. In this manner, the movements of chains 17, 18, 25and 26 are synchronized at all times.

Any adjustment for stretch or wear of the drive chains 17 and 18 and thestabilizing chains 25 and 26 by the adjusting screws 27, as described,adjusts the drive chain 17 and stabilizing chain 25 of the left-handpair of drive and stabilizing chains or adjusts the drive chain 18 andstabilizing chain 26 of the right-hand pair of drive and stabilizingchains the same amount, so that the synchronized relationship betweenthe drive and stabilizing chains of either pair is not disturbed by suchadjustment.

The synchronizing sprockets 36 comprise sprocket hubs 39 and sprocketdiscs 41 rotatably adjustable on the hubs 39. The discs 41? are held onthe hubs 39 of synchronizing sprockets 363 by bolts 41 engaged inthreaded apertures 42 (FIG. 4) in the hubs 39 and passing throughelongated arcuate slots 43 in the sprocket discs 40 to provide forrotary adjustment.

Referring to FIGS. 6, 7, 8 and 9, FIG. 8 shows the relationship of theparts when synchronizing chain 31 is new and unstretched, and shows theadjusted relative po sitions of the sprocket hub 39 and disc 41? ofsynchronizing sprocket 3&1 at this time. Now, assume a radial line R at12 oclock on each of sprockets 13, 22 and 30 and 12, 23 and 29. All suchradial lines R must at all times be at the same angular position ifsynchronism in the movements of drive and stabilizing chains 17 and 25is to be maintained at all times. In other words, the same orientation(indicated by radial lines R in the same angular position) of driveshafts 9 and 19 and stub shafts 14 and 24 must be maintained at alltimes (FIGS. 7 and 8).

However, a situation arises due to stretch or wear of synchronizingchain 31 such that adjustable idler sprocket 33 must be moved to aposition such as shown in FIGS. 6 and 9 to maintain the chain 31 taut.Assuming that shaft 9 remains fixed, the stretch in chain 31 taken up byadjusted sprocket 33 will rotate synchronizing sprocket 38' in acounter-clockwise direction. This in turn normally would involverotation of shaft 19 in a counterclockwise direction, and radial line Rassociated with shaft 19 would move toward 11 oclock.

Shaft 19, however, must not move in this manner if the same orientationof shafts 9 and 19 is to be maintained. Therefore, bolts 41 areloosened, permitting sprocket disc 40 to turn counter-clockwise as shownby the arrow 44 in FIG. 9 as the sprocket 33 is adjusted. However, hub39 of synchronizing sprocket 3t), and shaft 19 to which hub 39 is keyed,remain stationary, with the radial line R associated with shaft 19retained at the 12 oclock position. Radial line RA associated withsprocket disc 46, however, moves to a position such as shown in FIG. 9when disc turns counter-clockwise. After this adjustment is made, bolts41 are tightened and absolute synchronism in the movements of chains 17and 25 is maintained, despite adjustment of sprocket 33 to maintaintautness in the synchronizing chain 31 extending between the driveshafts 9 and 19.

Idler shafts 45 are mounted on each upper drive support member 5 belowdrive shafts 19, and a pair of sprockets 46 and 47 are mounted on idlershafts 45 engaged, respectively, with left-hand pair of drive andstabilizing chains 17 and 25. A similar pair of sprockets 48 and 49 aremounted on idler shaft 45 engaged, respectively, with the right-handpair of drive and stabilizing chains 18 and 26. These sprockets 46, 47,t8 and 49 are similar to sprockets performing a synchronizing functionin Pat. No. 2,949,810 bi they do not perform the synchronizing functionin the improved structure since there are no back-up sprocketsassociated therewith maintaining the chains 17, 18, 25 and 26 in properengagement with the sprockets. The purpose of sprockets 46, 47, 48 and19 is to hold the chains from sagging inward toward and bumping orrubbing portions of the upper drive support members 5 at the backside ofthe file (left-hand side of FIGS. 2 and 3). This sagging, bumping orrubbing can otherwise occur with heavy loading which may produce awave-like shape in the chain flights at the left of FIGS. 2 and 3.

Additional sprockets 55 mounted on stub shafts 51 on the lower drivesupport members 6 are provided for the same purpose, engaging the drivechains 17 and 18 (FIG. 2).

Rollers 52 journaled on shafts 53 preferably aligned with the axes ofdrive shafts 19 are mounted on the upper drive support members 5 withthe rollers 52 located immediately below and aligned with sprockets 13.The rollers 52 hold drive chains 17 and 18 from bumping or rubbing theupper drive support members 5 by any wavelike action of the chains thatmay result from heavy loading, as the chains pass around the upper idlersprockets 13 (FIGS. 1, 2 and 4).

Similarly, rollers 54 are journaled on main drive shaft 9 just above andaligned with stabilizing chain lower idler sprockets 23 (FIGS. 1, 3 and5) to prevent the stabilizing chains 25 and 26 from rubbing orburnpingthe lower drive support members 6.

The card-holding pans 55 are supported on and driven and stabilized bythe pairs of continuous drive and stabilizing chains 17-25, and 18-26 atthe ends of the pans 55 in the same manner shown in Pat. No. 2,940,810.Thus, each pan 55 is provided with a pair of aligned trunnions 56 and 57at its ends. Pairs of V-arranged forked levers S8 and 59 are mounted attheir inner ends, respectively, on the drive chains 17 and 18 and arepivoted at their outer ends, respectively, on trunnions 56 and 57. Thelevers 58 and 59 are equally spaced along the drive chains 17 and 18 asshown (FIG. 2), and a file with eight pans 55 is illustrated. However,the spacing of the V-arranged levers 58 and 59 along the drive chains isgreater than that shown in Pat. No. 2,940,810 to accommodate a greaterpan height, and taller cards carried by the pans. The increased loadingresulting from higher pans and taller cards gives rise to the wave-likechain action previously described, the main load of the pans 55 andcards therein being carried by the drive chains 17 and 18.

Connecting links 6% and 61 are fixed, at one end, respectively, totr-unnions 56 and 57 and are pivoted, respectively, at their other endsto V-arranged levers 62 and 63, the inner ends of which levers aremounted, respectively,

on stabilizing chains 25 and 26. .Thus, the stabilizing chains 25 and26, V-arranged levers 62 and 63 and connecting links 60 and 61 fixed onthe trunnions 56 and 57 of pans 55 maintain the pans 55 horizontalthroughout the orbit of pan travel.

The synchronized movements of the drive chains 17 and 18 and stabilizingchains 25 and'26, the orbits of travel of which are offset (spacingbetween shafts 14 and 19) a distance equal to the effective length ofconnecting links 60 and 61, maintain the pans 55, regardless of degreeand location of loading, pan height, or card size or height, inhorizontal positions at all times; and the drive mechanism operatessmoothly and noiselessly free of any tendency to jam, lock or bind thedrive or. to upset the pans.

Furthermore, the location of the main drive shaft 9, which extendsacross the file at its bottom region as shown in FIG. 1, eliminatesinterference between the shaft and the pans as the pans 55 move aroundtheir orbit of travel. Such interference would occur if the main driveshaft 9 were extended across the top of the file mechanism at thelocation of the stub shafts 14 for the upper idler sprockets 13.

This interference between the pans and a top located drive shaft couldbe avoided by increasing the lengths of the V-arranged levers 58, 59, 62and 63. This expedient, however, increases the height and width of theentire elevator file without any increase of card-holding capacity.Thus, the bottom drive cross-shaft arrangement provides a file ofgreater card capacity for a given size of file than when a top locatedcross-drive shaft is used.

The provision for radial adjustment between the sprocket hubs 39 andsprocket discs 49 of the synchronizing sprockets 30 has the furtheradvantage of permitting adjustment to provide a predetermined amount oflead or lag for the drive chains 17 and 18 with respect to thestabilizing chains 25 and 26 to take care of special loading conditionsthat may arise.

In the file illustrated, an inclined or slanted arrangement of a planepassing through shafts 14, 19, 9 and 24 is indicated and is preferred toprovide knee and foot room as well as a tray position closer to anoperator standing or seated in front of the file (right side of FIGS. 2,3 and 6). However, the improved capacity and synchronizing features ofthe construction are present in a file in which a plane passing throughthe shafts 14, 19, 9 and 24 is vertical rather than inclined.

The improved filing construction may be housed in any desired type ofcabinet, not shown, and may be equipped with any desired control andsafety device, not shown, such as those illustrated and described inPat. No. 2,940,810.

Accordingly, the present invention provides a new elevator fileconstruction in which absolute synchronism may be maintained of themovements of the drive and stabilizing chains on which the card-holdingpans are mounted, without limitation as to spacing between pans, amountof pan loading, or height or size of cards carried by the pans; providesa construction in which the synchro-drive operates smoothly andnoiselessly, free of tendency to jam, lock or bind the drive, or toupset the pans; provides a construction in which the pans are supportedand driven from both ends with cross drive shaft means located such asto provide a file of any given size with maximum cardcarrying capacity;and provides a construction eliminating difiiculties heretoforeencountered, achieving the stated objects, accomplishing the many newfunctions and results described, and solving problems of limited pansize, card size, pan loading, etc., existing in the art.

In the, foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, becausesuchterms are used for descriptive purposes and are intended to be bfoad- Ily construed.

Moreover, the description and illustration of the invention is by way ofexample and the scope of the invention is not limited to the exactstructure shown, because the sizes, shapes, and directions of movementof the various parts and components may be varied to provide otherstructural embodiments, without departing from the fundamentalsynchro-drive and maximum capacity principles of the invention.

Having now described the features, discoveries and principles of theinvention, the assembly, characteristics, operation and use of apreferred form thereof, and the advantageous, new and useful resultsobtained thereby; the new and useful discoveries, principles, apparatus,combinations, parts, elements, subcombinations, structures, cooperativerelationships and arrangements, and mechanical equivalents obvious tothose skilled in the art are set forth in the appended claims.

I claim:

1. In elevator file construction, spaced first and second upright framesupport members, a first pair of offset continuous drive and stabilizingchains located adjacent the first frame support member, a second pair ofoffset continuous drive and stabilizing chains located adjacent thesecond frame support member, a plurality of card-holding pans eachsupported at one end on the first pair and at the otherend on the secondpair of drive and stabilizing chains, a main drive shaft extendingbetween and journaled on the spaced support members, a first stabilizingchain drive shaft journaled on the first frame support member spacedfrom said main drive shaft, a second stabilizing chain drive shaftaxially aligned with said first stabilizing chain drive shaft journaledon the second frame support member, a first pair of sprockets for thefirst drive chain including a drive sprocket fixed to the main driveshaft and an idler sprocket journaled on the first frame support member,a second pair of sprockets for the second drive chain including a drivesprocket also fixed to the main drive shaft and an idler sprocketjournaled on the second frame support member, a third pair of sprocketsfor the first stabilizing chain including a drive sprocket fixed to saidfirst stabilizing chain drive shaft and an idler sprocket journaled onthe first frame support member, a fourth pair of sprockets for thesecond stabilizing chain including a drive sprocket fixed to said secondstabilizing chain drive shaft and an idler sprocket journaled on thesecond frame support member, a fifth pair of synchronizing sprocketsincluding a drive sprocket fixed to said main drive shaft and a drivesprocket fixed to said first stabilizing chain drive shaft, a sixth pairof synchronizing sprockets including a drive sprocket also fixed to saidmain drive shaft and a drive sprocket fixed to said.

second stabilizing chain drive shaft, the sprockets of each pairbeingaligned and spaced above one another, a first continuousinter-connecting chain trained around the fifth pair of synchronizingsprockets, a second continuous inter-connecting chain trained around thesixth pair of synchronizing sprockets, motor-drive means for the maindrive shaft, and means for adjusting the inter-connecting chain andsynchronizing sprocket driving connections between the main drive shaftand the first and second stabilizing chain drive shafts to maintainmatching angular orientation of the main, first and second drive shaftswhereby synchronous movements of the drive and stabilizingchains aremaintained.

2.'The construction defined in claim 1 in which the means for adjustingthe inter-connecting chain and synchronizing sprocket drivingconnections to maintain said matching angular orientation includes anadjustable idler sprocket mounted one on each of the first and secondframe support members and engaged respectively with the first and secondinter-connecting chains for maintaining 3. The construction defined inclaim 2 in which the rotatably adjustable synchronizing sprocketincludes a sprocket hub fixed to the drive shaft on which the sprocketis mounted, a sprocket disc rotatably mounted on the hub, and bolt andslot means for clamping the disc to the hub in any desired position ofrotary adjustment.

4. The construction defined in claim 2 in which the main drive shaftextends between the first and second upright frame support members atthe lower ends of said support members.

References Cited by the Examiner UNITED STATES PATENTS Buckingham312-268 X Holland-Letz 198-438 X Templeton 198-9 Fergason 198208 XGraber 312-268 Cordis 198137 FRANK B. SHERRY, Primary Examiner.

1. IN ELEVATOR FILE CONSTRUCTION, SPACED FIRST AND SECOND UPRIGHT FRAMESUPPORT MEMBERS, A FIRST PAIR OF OFFSET CONTINUOUS DRIVE AND STABILIZINGCHAINS LOCATED ADJACENT THE FIRST FRAME SUPPORT MEMBER, A SECOND PAIR OFOFFSET CONTINUOUS DRIVE AND STABILIZING CHAINS LOCATED ADJACENT THESECOND FRAME SUPPORT MEMBER, A PLURLITY OF CARD-HOLDING PANS EACHSUPPORTED AT ONE END ON THE FIRST PAIR AND AT THE OTHER END ON THESECOND PAIR OF DRIVE AND STABILIZING CHAINS, A MAIN DRIVE SHAFTEXTENDING BETWEEN AND JOURNALED ON THE SPACED SUPPORT MEMBERS, A FIRSTSTABILIZING CHAIN DRIVE SHAFT JOURNALED ON THE FIRST FRAME SUPPORTMEMBER SPACED FROM SAID MAIN DRIVE SHAFT, A SECOND STABILIZING CHAINDRIVE SHAFT AXIALLY ALIGNED WITH SAID FIRST STABLIZING CHAIN DRIVE SHAFTJOURNALED ON THE SECOND FRAME SUPPORT MEMBER, A FIRST PAIR OF SPROCKETSFOR THE FIRST DRIVE CHAIN INCLUDING A DRIVE SPROCKET FIXED TO THE MAINDRIVE SHAFT AND AN IDLER SPROCKET JOURNALED ON THE FIRST FRAME SUPPORTMEMBER, A SECOND PAIR OF SPROCKETS FOR THE SECOND DRIVE CHAIN INCLUDINGA DRIVE SPROCKET ALSO FIXED TO THE MAIN DRIVE SHAFT AND AN IDLERSPROCKET JOURNALED ON THE SECOND FRAME SUPPORT MEMBER, A THIRD PAIR OFSPROCKETS FOR THE FIRST STABILIZING CHAIN INCLUDING A DRIVE SPROCKETFIXED TO SAID FIRST STABILIZING CHAIN DRIVE SHAFT AND AN IDLER SPROCKETJOURNALED ON THE FIRST FRAME SUPPORT MEMBER, A FOURTH PAIR OF SPROCKETSFOR THE SECOND STABILIZING CHAIN INCLUDING A DRIVE SPROCKET FIXED TOSAID SECOND STABILIZING CHAIN DRIVE SHAFT AND AN IDLER SPROCKETJOURNALED ON THE SECOND FRAME SUPPORT MEMBER, A FIFTH PAIR OFSYNCHRONIZING SPROCKETS INCLUDING A DRIVE SPROCKET FIXED TO SAID MAINDRIVE SHAFT AND A DRIVE SPROCKET FIXED TO SAID